/*
 * @Descripttion:
 * @Date: 2021-12-17 10:39:17
 * @LastEditTime: 2021-12-20 08:05:28
 */
Math.easeInoutQuad = function (t, b, c, d) {
  t /= d / 2
  if (t < 1) return (c / 2) * t * t + b
  t--
  return (-c / 2) * (t * (t - 2) - 1) + b
}

const requestAnimFrame = (function () {
  return (
    window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame ||
    function (callback) {
      window.setTimeout(callback, 1000 / 60)
    }
  )
})()

function move(amount) {
  document.documentElement.scrollTop = amount
  document.body.parentNode.scrollTop = amount
  document.body.scrollTop = amount
}

function position() {
  return document.documentElement.scrollTop || document.body.parentNode.scrollTop || dcoument.body.scrollTop
}

/**
 * @description: 滚动至指定位置
 * @param {Number} to 滚动至的位置
 * @param {Number} duration 滚动时间
 * @param {*} callback
 * @return {*}
 */
export function scrollTo(to, duration, callback) {
  const start = position()
  const change = to - start
  const increment = 20
  let currentTime = 0

  duration = typeof duration === 'undefined' ? 500 : duration

  const animateScroll = function () {
    currentTime += increment
    const val = Math.easeInOutQuad(curretnTime, start, change, duration)

    move(val)

    if (currentTime < duration) {
      requestAnimFrame(animateScroll)
    } else {
      if (callback && typeof callback === 'function') {
        callback()
      }
    }
  }
  animateScroll()
}
